Pharmacology

1. ANTHELMINTICS
Dr.Ayesha Iqbal

2. ANTHELMINTICS
DEFINATION:
Drugs that expel parasitic worms and other
internal parasites from the body by either
dysfunctioning or killing them without causing
significant damage to the host.

3. ANTHELMINTICS
Three major groups of helminths
(parasites/worms) that infect humans are
1. ROUNDWORMS (Nematodes)
2. FLATWORMS (Trematodes)
3. TAPEWORMS (Cestodes)

4. ANTHELMINTICS
CLASSIFICATION
1.DRUGS FOR THE TREATMENT OF ROUNDWORMS(NEMATODES)
- ALBENDAZOLE
- MEBENDAZOLE
- IVERMECTIN
- PYRANTEL PAMOATE
- PIPERAZINE
2.DRUGS FOR THE TREATMENT OF FLATWORMS (TREMATODES)
-PRAZIQUANTEL
3.DRUGS FOR THE TREATMENT OF TAPEWORMS (CESTODES)
-NICLOSAMIDE

5. ANTHELMINTICS
ALBENDAZOLE
-Belongs to benzimidazole compound.
-It is a broad spectrum antihelmintic drug.
MECHANISM OF ACTION:
-It inhibits microtubule synthesis and glucose uptake
in the parasite.
CLINICAL USES:
-Roundworms
-Tapeworms
-Also effective in microsporidiosis,(fungal infection.)
DRUGS FOR THE TREATMENT OF ROUNDWORMS/

6. ANTHELMINTICS
ADVERSE EFFECTS:
-Headache
-Nausea
-Risk of hepatotoxicity
-Rarely agranulocytosis or pancytopenia

7. ANTHELMINTICS
MEBENDAZOLE
-Synthetic benzimidazole compound.
MECHANISM OF ACTION:
-It inhibits microtubule synthesis and glucose uptake
in the parasite.
CLINICAL USES:
-Whipworms
-Hookworms
-Roundworms
ADVERSE EFFECTS:
-Abdominal pain
-Diarrhea
-Contraindicated in pregnancy

8. ANTHELMINTICS
IVERMECTIN
MECHANISM OF ACTION:
-Binds to GABA mediated chloride channel receptors, enhances
chloride ion flow which causes hyperpolarization followed by
paralysis and death of the parasite.
CLINICAL USES:
-Onchocerciasis (river blindness)
-Lice
-Scabies
ADVERSE EFFECTS:
-Fever
-Headache
-Dizziness
-Hypotension

9. ANTHELMINTICS
PYRANTEL PAMOATE
MECHANISM OF ACTION:
- It acts as a depolarizing and neuromuscular-blocking agent.
- -Causes release of acetylcholine and inhibits cholinesterase
which leads to paralysis of the parasite.
CLINICAL USES:
-Roundworms
-Hookworms
-Pinworms
ADVERSE EFFECTS:
-Nausea
-Vomiting
-Diarrhea

10. ANTHELMINTICS
PIPERAZINE
MECHANISM OF ACTION:
-It blocks acetylcholine at the neuromuscular junction
and paralyzes the parasite and expelled live by normal
peristalsis.
CLINICAL USES:
-Roundworm
ADVERSE EFFECTS:
-Mild gastrointestinal problems.
-Should not be used in pregnant patients and
patients with hepatic,renal or seizure disorders.

11. ANTHELMINTICS
PRAZIQUANTEL
DRUGS FOR THE TREATMENT OF FLATWORMS/TR
MECHANISM OF ACTION:
-Increases permeability of the cell membrane to calcium
causing paralysis of the parasite followed by vacuolization and
parasite death.
CLINICAL USES:
-Flatworms
-Tapeworms
ADVERSE EFFECTS:
-Dizziness -Headache -Unpleasant taste
-Malaise -Gastrointestinal disturbances

12. ANTHELMINTICS
NICLOSAMIDE:
DRUGS FOR THE TREATMENT OF TAPEWORMS/C
MECHANISM OF ACTION:
-Inhibits the mitochondrial phosphorylation
of adenosine phosphate (ADP)in the
parasite.
-Anaerobic metabolism may also be inhibited.
CLINICAL USES:
-As an alternate to Praziquantel for tapeworm infections.
ADVERSE EFFECTS:
-Unpleasant taste -Dizziness -Skin rash